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Unformatted text preview: For each of the following scenarios, use complete English sentences to identify the W’s, name the variables, specify for each variable whether its use indicates that it should be treated as categorical or quantitative, and for any quantitative variable, identify the units in which it was measured (or note that they were not provided). In other words, carefully describe the population of interest, the sample, the variable (and identify whether the variable should be treated as categorical or quantitative), the parameter, and the statistic. 1. A quality-control technician at Boeing wants to know what proportion of all airplane seat bolts
are defective. However, it is impossible for him and his team to inspect every one of the hundreds of thousands of bolts. So, he randomly selects five thousand airplane seat bolts and records whether-or-not each is defective; there were 107 defective bolts. He then computes the fraction of those five thousand bolts that are defective. 2. Eveready, a battery manufacturer, wants to determine the average mean life of its AA battery
in hopes of making an advertisement that claims that this average is at least 300 minutes. A random sample of 100 batteries is gathered, the lifespan of each is measured and recorded in minutes, and the average lifespan of these hundred batteries is found to be 298 minutes. 3. The Food and Nutrition Board of the National Academy of Sciences reports that the average
daily sodium intake for all Americans does not exceed 3,300 mg. In a study by Consumer Reports, a random sample of 10,000 U.S. residents was found to have an average daily sodium intake of 4,600 mg. ...
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This note was uploaded on 10/03/2010 for the course MATH Math 211 taught by Professor Sarahleyden during the Spring '10 term at Shoreline.
- Spring '10